2. (Zo["o]l.) A genus of insects including the day flies, or ephemeral flies. See Ephemeral fly, under Ephemeral.May \May\, n. [F. Mai, L. Maius; so named in honor of the goddess Maia (Gr. ?), daughter of Atlas and mother of Mercury by Jupiter.] 1. The fifth month of the year, containing thirty-one days. --Chaucer.

2. The early part or springtime of life.

His May of youth, and bloom of lustihood. --Shak.

3. (Bot.) The flowers of the hawthorn; -- so called from their time of blossoming; also, the hawthorn.

The palm and may make country houses gay. --Nash.

Plumes that micked the may. --Tennyson.

4. The merrymaking of May Day. --Tennyson.

Italian may (Bot.), a shrubby species of Spir[ae]a (S. hypericifolia) with many clusters of small white flowers along the slender branches.

May apple (Bot.), the fruit of an American plant (Podophyllum peltatum). Also, the plant itself (popularly called mandrake), which has two lobed leaves, and bears a single egg-shaped fruit at the forking. The root and leaves, used in medicine, are powerfully drastic.

May beetle, May bug (Zo["o]l.), any one of numerous species of large lamellicorn beetles that appear in the winged state in May. They belong to Melolontha, and allied genera. Called also June beetle.

May Day, the first day of May; -- celebrated in the rustic parts of England by the crowning of a May queen with a garland, and by dancing about a May pole.

May dew, the morning dew of the first day of May, to which magical properties were attributed.

May flower (Bot.), a plant that flowers in May; also, its blossom. See Mayflower, in the vocabulary.

May fly (Zo["o]l.), any species of Ephemera, and allied genera; -- so called because the mature flies of many species appear in May. See Ephemeral fly, under Ephemeral.

May game, any May-day sport.

May lady, the queen or lady of May, in old May games.

May lily (Bot.), the lily of the valley (Convallaria majalis).

May pole. See Maypole in the Vocabulary.

May queen, a girl or young woman crowned queen in the sports of May Day.

lasting for only a short time:- Fame in the world of rock and pop is largely ephemeral.

ephemera

plural noun

the type of objects which, when they were produced, were not intended to last a long time or were specially produced for one occasion:- Amongst other pop ephemera, the auction will be selling off rock stars' stage clothes.

The definition of Ephemera comes to us from the Greek ‘epi’ (about) and ‘hemeris’ (day). Ephemera is pronounced “efem’mera” The comtempory definition of ephemera is, “something short lived or transitory” especially all types of paper documents both printed or handwritten produced for a specific purpose and normally intended for disposal.Examples include advertising trade cards similar to the Warner’s Yeast card above which relates to Haley’s Comet. Other examples would include auction broadsides, posters, greeting cards, Rewards of Merit, tickets, invitations, Sheet Music, Candy Boxes, illustrated letter or billheads, The list goes on & on and is endless due to the history of printed and manuscript commercial or entertainment documents. Durable Ephemera are those Advertising Signs, Souveniers and Tin or Wooden Advertising Boxes, ect.Paper Ephemera has been well documented in John Lewis’s 1962 book, “Printed Ephemera”, (the 20th century Bible of Ephemera) where John documents Ephemera from as early as the 16th century to present times. from:http://www.ephemeranet.com/Ephemera/ephemera.html

Great suggestion, Katy ; this noun - in particular, its all too rarely used singular form - and the adjective and abstract noun formed from it certainly merit consideration as Good Words of the Day....

I had never linked the insects to stars, but
Ephemeris
From Wikipedia, the free encyclopedia.
An ephemeris (plural: ephemerides) (from the Greek word ephemeros= daily) was, traditionally, a table providing the positions (given in a Cartesian coordinate system, or in right ascension and declination or, for astrologers, in longitude along the zodiacal ecliptic), of the Sun, the Moon, and the planets in the sky at a given moment in time; the astrological positions are usually given for either noon or midnight depending on the particular ephemeris that is used.